The present invention is directed to a receptacle, such as a pan, which is adaptable for nested stacking.
The advantages of nested stacking of receptacles for storage have long been recognized. Principal among those advantages is the reduced space occupied during storage, and a lesser susceptibility to damage of receptacles stored in a nested orientation.
The employment of shoulders, flutes, corrugations, embossings, ridges, and other means of enlarging the perimeter of a receptacle to preclude jamming of adjacent receptacles during nested stacking is known. For example, U.S. Pat. No. 3,233,812 to T. B. Kennedy, for a "Molded Pulp Container", discloses a bumper 16 to provide a nesting capability; U.S. Pat. No. 4,113,095 to Dietz et al., for "Tray-Type Processed Food Containers", discloses horizontal corner corrugations 15 and wider corner ledge portions 19 to provide a nesting capability; U.S. Pat. No. 4,298,156 to Reifers et al., for "Nestable and Denestable Molded Egg Cartons", discloses narrow lobes 41 and wide lobes 40 to provide a nesting capability; U.S. Pat. No. 4,660,734 to Heaney et al., for a "Steam Table Pan", discloses a gusset 50 to provide a nesting capability; and U.S. Pat. No. 4,828,112 to Vollrath et al., for a "Metal Transport Pan", discloses an outwardly-protruding ridge 40 to provide a nesting capability.
Similar structures are disclosed in U.S. Pat. No. Des. D277,632 to Staufenberg, for a "Food Storage Dish"; and Design Patent No. D277,993 to Sinchok, for a "Stackable Utility Basket".
Still further, the employment of a shoulder or similar structure to prevent jamming during nested stacking is disclosed in a Rubbermaid Commercial Product Incorporated brochure entitled "Rubbermaid Food Specialists", dated May, 1978; in a Cambro "Product News" flyer, No. 25, dated Nov. 15, 1978; in a Vollrath product brochure, Form No. 35001, dated 1986; in a Polar Ware "Food Service" product brochure, dated May, 1988; and in a 1989 Cambro Catalog, dated Jan. 1, 1989.
Thus, the employment of shoulders or similar structures to increase the perimetric dimensions of a receptacle to provide a nestable stacking capability is known. However, problems with jamming of adjacent nested receptacles employing such structures are still experienced.
Such adjacent receptacles may jam because of interaction between walls of the adjacent receptacles. That is, such receptacles are often stacked during normal use in a wet condition and a suction effect between adjacent walls can be experienced which will render separation of the adjacent receptacles more difficult, and further serves to impede drying of such adjacent stacked receptacles.
All of the earlier structures which employ integrally formed shoulder-type structures at corners of a receptacle to provide a nesting capability provide a straight-drop structure for the shoulder structure. That is, the shoulder depends vertically downward in its departure from the corner. With such a straight-drop structure, the taper of the side walls of the receptacle provides the displacement which gives rise to a nesting stop surface presented by the shoulder to a next adjacent receptacle in a nested orientation. In such structures, variations in manufacturing tolerances or flexibility of receptacle walls may present improper clearances between adjacent receptacles. Such improper clearances may enable an upper receptacle to slip within a lower receptacle and jam in the lower receptacle, even with the projecting shoulder or other structure present, thereby rendering de-nesting of the two receptacles difficult.
The present invention provides a receptacle adaptable for nested stacking which presents a firm seat for nested stacking which will better accommodate dimensional differences among receptacles than did prior art structures, which limits contact between adjacent receptacles to areas in the vicinity of the corners of the receptacles, and which provides a stand-off between walls of adjacent nested receptacles to preclude creation of a suction effect between adjacent such receptacles, as well as to promote drying of stacked receptacles.